CVE-2026-97443
Received Received - Intake

Kernel panic risk in Linux perf ftrace function unregister

Vulnerability report for CVE-2026-97443, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-09-24

Last updated on: 2026-09-24

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: perf/ftrace: Fix WARNING in __unregister_ftrace_function perf_ftrace_function_unregister() unconditionally calls unregister_ftrace_function() without checking whether the ftrace_ops was ever successfully registered. This triggers a WARN_ON in __unregister_ftrace_function() when the ops doesn't have FTRACE_OPS_FL_ENABLED set. This can happen during perf_event_alloc() error cleanup when perf_trace_destroy() is called via __free_event() on an event whose ftrace_ops registration failed or was already torn down by perf_try_init_event()'s err_destroy path. The call path is: perf_event_alloc() error cleanup -> __free_event() -> event->destroy() [tp_perf_event_destroy] -> perf_trace_destroy() -> perf_trace_event_close() -> TRACE_REG_PERF_CLOSE -> perf_ftrace_function_unregister() -> unregister_ftrace_function() -> __unregister_ftrace_function() -> WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)) Fix this by checking FTRACE_OPS_FL_ENABLED before attempting to unregister. If the ops is not enabled, just free the filter and return success.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-09-24
Last Modified
2026-09-24
Generated
2026-09-24
AI Q&A
2026-09-24
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This is a Linux kernel vulnerability where perf_ftrace_function_unregister() calls unregister_ftrace_function() without checking if ftrace_ops was properly registered. This triggers a warning in __unregister_ftrace_function() when the ops lacks FTRACE_OPS_FL_ENABLED flag, typically during error cleanup in perf_event_alloc().

Detection Guidance

This vulnerability is specific to the Linux kernel's perf/ftrace functionality and does not have a direct network detection method. It may be detected by checking kernel logs for WARN_ON messages related to ftrace operations or by examining kernel crash dumps for traces involving perf_ftrace_function_unregister().

Impact Analysis

This vulnerability may cause kernel warnings or errors during system operations involving perf events. It could lead to system instability or crashes when perf event cleanup occurs after failed registrations.

Mitigation Strategies

Update your Linux kernel to the latest stable version that includes the fix for this issue. If immediate updating is not possible, avoid using perf tools with ftrace functionality until the kernel is updated.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-97443. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart